气候变化领域集成服务门户(CCPortal): Polaronic behavior in a weak-coupling superconductor

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DOI	10.1073/pnas.1713916115
	Polaronic behavior in a weak-coupling superconductor
	Swartz A.G.; Inoue H.; Merz T.A.; Hikita Y.; Raghu S.; Devereaux T.P.; Johnston S.; Hwang H.Y.
发表日期	2018
ISSN	0027-8424
起始页码	1475
结束页码	1480
卷号	115 期号:7
英文摘要	The nature of superconductivity in the dilute semiconductor SrTiO3 has remained an open question for more than 50 y. The extremely low carrier densities (1018–1020 cm−3) at which superconductivity occurs suggest an unconventional origin of superconductivity outside of the adiabatic limit on which the Bardeen–Cooper–Schrieffer (BCS) and Migdal–Eliashberg (ME) theories are based. We take advantage of a newly developed method for engineering band alignments at oxide interfaces and access the electronic structure of Nb-doped SrTiO3, using high-resolution tunneling spectroscopy. We observe strong coupling to the highest-energy longitudinal optic (LO) phonon branch and estimate the doping evolution of the dimensionless electron–phonon interaction strength (λ). Upon cooling below the superconducting transition temperature (Tc), we observe a single superconducting gap corresponding to the weak-coupling limit of BCS theory, indicating an order of magnitude smaller coupling (λBCS ≈ 0.1). These results suggest that despite the strong normal state interaction with electrons, the highest LO phonon does not provide a dominant contribution to pairing. They further demonstrate that SrTiO3 is an ideal system to probe superconductivity over a wide range of carrier density, adiabatic parameter, and electron–phonon coupling strength. © 2018 National Academy of Sciences. All Rights Reserved.
英文关键词	Electronic structure; Oxide interface; Polaron; Superconductivity
语种	英语
scopus关键词	Article; controlled study; electron; molecular interaction; phonon; priority journal; superconductivity; transition temperature
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160543
作者单位	Swartz, A.G., Department of Applied Physics, Stanford University, Stanford, CA 94305, United States, Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, United States, Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA 94305, United States; Inoue, H., Department of Applied Physics, Stanford University, Stanford, CA 94305, United States, Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, United States, Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA 94305, United States; Merz, T.A., Department of Applied Physics, Stanford University, Stanford, CA 94305, United States, Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA 94305, United States; Hikita, Y., Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Stanford Univ...
推荐引用方式 GB/T 7714	Swartz A.G.,Inoue H.,Merz T.A.,et al. Polaronic behavior in a weak-coupling superconductor[J],2018,115(7).
APA	Swartz A.G..,Inoue H..,Merz T.A..,Hikita Y..,Raghu S..,...&Hwang H.Y..(2018).Polaronic behavior in a weak-coupling superconductor.Proceedings of the National Academy of Sciences of the United States of America,115(7).
MLA	Swartz A.G.,et al."Polaronic behavior in a weak-coupling superconductor".Proceedings of the National Academy of Sciences of the United States of America 115.7(2018).